Spatial power-combining devices, such as a Qorvo® Spatium® spatial power-combining device, are used for broadband radio frequency power amplification in commercial and defense communications, radar, electronic warfare, satellite, and various other communication systems. Spatial power-combining techniques are implemented by combining broadband signals from a number of amplifiers to provide output powers with high efficiencies and operating frequencies. One example of a spatial power-combining device utilizes a plurality of solid-state amplifier assemblies that form a coaxial waveguide to amplify an electromagnetic signal. Each amplifier assembly may include an input antenna structure, an amplifier, and an output antenna structure. When the amplifier assemblies are combined to form the coaxial waveguide, input antennas may form an input antipodal antenna array, and output antennas may form an output antipodal antenna array.
In operation, an electromagnetic signal is passed through an input port to an input coaxial waveguide section of the spatial power-combining device. The input coaxial waveguide section distributes the electromagnetic signal to be split across the input antipodal antenna array. The amplifiers receive the split signals and in turn transmit amplified split signals across the output antipodal antenna array. The output antipodal antenna array and an output coaxial waveguide section combine the amplified split signals to form an amplified electromagnetic signal that is passed to an output port of the spatial power-combining device.
Performance of spatial power-combining devices depends on a number of parameters, including size, spacing, and number of amplifier assemblies in a particular device. For example, the size and spacing of the amplifier assemblies in a coaxial arrangement about a center axis are relatively important for a given operation frequency range and bandwidth of the spatial-power combining device. If the spacing between the amplifier assemblies is too great, the device does not function; and if the spacing between the amplifier assemblies is too close, there may be interference. Additionally, the output power of a spatial-power combining device is proportional to the number of amplifier assemblies in a particular device.